function md5(md5str) {
  var createMD5String = function (string) {
    var x = Array()
    var k, AA, BB, CC, DD, a, b, c, d
    var S11 = 7,
      S12 = 12,
      S13 = 17,
      S14 = 22
    var S21 = 5,
      S22 = 9,
      S23 = 14,
      S24 = 20
    var S31 = 4,
      S32 = 11,
      S33 = 16,
      S34 = 23
    var S41 = 6,
      S42 = 10,
      S43 = 15,
      S44 = 21
    string = uTF8Encode(string)
    x = convertToWordArray(string)
    a = 0x67452301
    b = 0xEFCDAB89
    c = 0x98BADCFE
    d = 0x10325476
    for (k = 0; k < x.length; k += 16) {
      AA = a
      BB = b
      CC = c
      DD = d
      a = FF(a, b, c, d, x[k + 0], S11, 0xD76AA478)
      d = FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756)
      c = FF(c, d, a, b, x[k + 2], S13, 0x242070DB)
      b = FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE)
      a = FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF)
      d = FF(d, a, b, c, x[k + 5], S12, 0x4787C62A)
      c = FF(c, d, a, b, x[k + 6], S13, 0xA8304613)
      b = FF(b, c, d, a, x[k + 7], S14, 0xFD469501)
      a = FF(a, b, c, d, x[k + 8], S11, 0x698098D8)
      d = FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF)
      c = FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1)
      b = FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE)
      a = FF(a, b, c, d, x[k + 12], S11, 0x6B901122)
      d = FF(d, a, b, c, x[k + 13], S12, 0xFD987193)
      c = FF(c, d, a, b, x[k + 14], S13, 0xA679438E)
      b = FF(b, c, d, a, x[k + 15], S14, 0x49B40821)
      a = GG(a, b, c, d, x[k + 1], S21, 0xF61E2562)
      d = GG(d, a, b, c, x[k + 6], S22, 0xC040B340)
      c = GG(c, d, a, b, x[k + 11], S23, 0x265E5A51)
      b = GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA)
      a = GG(a, b, c, d, x[k + 5], S21, 0xD62F105D)
      d = GG(d, a, b, c, x[k + 10], S22, 0x2441453)
      c = GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681)
      b = GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8)
      a = GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6)
      d = GG(d, a, b, c, x[k + 14], S22, 0xC33707D6)
      c = GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87)
      b = GG(b, c, d, a, x[k + 8], S24, 0x455A14ED)
      a = GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905)
      d = GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8)
      c = GG(c, d, a, b, x[k + 7], S23, 0x676F02D9)
      b = GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A)
      a = HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942)
      d = HH(d, a, b, c, x[k + 8], S32, 0x8771F681)
      c = HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122)
      b = HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C)
      a = HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44)
      d = HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9)
      c = HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60)
      b = HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70)
      a = HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6)
      d = HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA)
      c = HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085)
      b = HH(b, c, d, a, x[k + 6], S34, 0x4881D05)
      a = HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039)
      d = HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5)
      c = HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8)
      b = HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665)
      a = II(a, b, c, d, x[k + 0], S41, 0xF4292244)
      d = II(d, a, b, c, x[k + 7], S42, 0x432AFF97)
      c = II(c, d, a, b, x[k + 14], S43, 0xAB9423A7)
      b = II(b, c, d, a, x[k + 5], S44, 0xFC93A039)
      a = II(a, b, c, d, x[k + 12], S41, 0x655B59C3)
      d = II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92)
      c = II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D)
      b = II(b, c, d, a, x[k + 1], S44, 0x85845DD1)
      a = II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F)
      d = II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0)
      c = II(c, d, a, b, x[k + 6], S43, 0xA3014314)
      b = II(b, c, d, a, x[k + 13], S44, 0x4E0811A1)
      a = II(a, b, c, d, x[k + 4], S41, 0xF7537E82)
      d = II(d, a, b, c, x[k + 11], S42, 0xBD3AF235)
      c = II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB)
      b = II(b, c, d, a, x[k + 9], S44, 0xEB86D391)
      a = addUnsigned(a, AA)
      b = addUnsigned(b, BB)
      c = addUnsigned(c, CC)
      d = addUnsigned(d, DD)
    }
    var tempValue = wordToHex(a) + wordToHex(b) + wordToHex(c) + wordToHex(d)
    return tempValue.toLowerCase()
  }
  var rotateLeft = function (lValue, iShiftBits) {
    return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits))
  }
  var addUnsigned = function (lX, lY) {
    var lX4, lY4, lX8, lY8, lResult
    lX8 = (lX & 0x80000000)
    lY8 = (lY & 0x80000000)
    lX4 = (lX & 0x40000000)
    lY4 = (lY & 0x40000000)
    lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF)
    if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8)
    if (lX4 | lY4) {
      if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8)
      else return (lResult ^ 0x40000000 ^ lX8 ^ lY8)
    } else {
      return (lResult ^ lX8 ^ lY8)
    }
  }
  var F = function (x, y, z) {
    return (x & y) | ((~x) & z)
  }
  var G = function (x, y, z) {
    return (x & z) | (y & (~z))
  }
  var H = function (x, y, z) {
    return (x ^ y ^ z)
  }
  var I = function (x, y, z) {
    return (y ^ (x | (~z)))
  }
  var FF = function (a, b, c, d, x, s, ac) {
    a = addUnsigned(a, addUnsigned(addUnsigned(F(b, c, d), x), ac))
    return addUnsigned(rotateLeft(a, s), b)
  }
  var GG = function (a, b, c, d, x, s, ac) {
    a = addUnsigned(a, addUnsigned(addUnsigned(G(b, c, d), x), ac))
    return addUnsigned(rotateLeft(a, s), b)
  }
  var HH = function (a, b, c, d, x, s, ac) {
    a = addUnsigned(a, addUnsigned(addUnsigned(H(b, c, d), x), ac))
    return addUnsigned(rotateLeft(a, s), b)
  }
  var II = function (a, b, c, d, x, s, ac) {
    a = addUnsigned(a, addUnsigned(addUnsigned(I(b, c, d), x), ac))
    return addUnsigned(rotateLeft(a, s), b)
  }
  var convertToWordArray = function (string) {
    var lWordCount
    var lMessageLength = string.length
    var lNumberOfWordsTempOne = lMessageLength + 8
    var lNumberOfWordsTempTwo = (lNumberOfWordsTempOne - (lNumberOfWordsTempOne % 64)) / 64
    var lNumberOfWords = (lNumberOfWordsTempTwo + 1) * 16
    var lWordArray = Array(lNumberOfWords - 1)
    var lBytePosition = 0
    var lByteCount = 0
    while (lByteCount < lMessageLength) {
      lWordCount = (lByteCount - (lByteCount % 4)) / 4
      lBytePosition = (lByteCount % 4) * 8
      lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition))
      lByteCount++
    }
    lWordCount = (lByteCount - (lByteCount % 4)) / 4
    lBytePosition = (lByteCount % 4) * 8
    lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition)
    lWordArray[lNumberOfWords - 2] = lMessageLength << 3
    lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29
    return lWordArray
  }
  var wordToHex = function (lValue) {
    var WordToHexValue = '',
      WordToHexValueTemp = '',
      lByte, lCount
    for (lCount = 0; lCount <= 3; lCount++) {
      lByte = (lValue >>> (lCount * 8)) & 255
      WordToHexValueTemp = '0' + lByte.toString(16)
      WordToHexValue = WordToHexValue + WordToHexValueTemp.substr(WordToHexValueTemp.length - 2, 2)
    }
    return WordToHexValue
  }
  var uTF8Encode = function (string) {
    string = string.toString().replace(/\x0d\x0a/g, '\x0a')
    var output = ''
    for (var n = 0; n < string.length; n++) {
      var c = string.charCodeAt(n)
      if (c < 128) {
        output += String.fromCharCode(c)
      } else if ((c > 127) && (c < 2048)) {
        output += String.fromCharCode((c >> 6) | 192)
        output += String.fromCharCode((c & 63) | 128)
      } else {
        output += String.fromCharCode((c >> 12) | 224)
        output += String.fromCharCode(((c >> 6) & 63) | 128)
        output += String.fromCharCode((c & 63) | 128)
      }
    }
    return output
  }
  return createMD5String(md5str)
}
module.exports = {
  md5: md5
}